A legend had it that the site where the church was eventually erected was haunted by the ghost of Nero, the Roman Emperor. On his burial ground had grown a bewitched walnut tree full of crows. To put an end to this myth, Pope Paschal II in 1099 ordered the tree to be cut down and commissioned a Romanesque chapel to be built instead. In 1513, various of the most influential artists of the period, like Pinturicchio, Raphael, Caravaggio and Bernini were requested to decorate the walls and ceilings of the temple. Santa Maria del Popolo's decoration is unlike any other church in Rome. Among the beautiful art work found in the church, it is worth highlighting the Chapel Cerasi, which houses two canvases by Caravaggio from 1600, and the Chapel Chigi, built and decorated by Raphael. The Basilica of Santa Maria del Popolo is one of these that are definitely worth visiting, not because of its structure or its façade, but because of its impressively decorated chapels.

Sant'Agostino in Campo Marzio is an important 15th century minor basilica and parish church in the rione Sant'Eustachio. The Madonna di Loreto (or Pilgrim’s Madonna) was commissioned from Caravaggio thanks to a legacy left by Ermete Cavalletti for the family chapel in Sant’Agostino. The subject had been specified by the contract of 1603 as the deceased Marquis was devoted to Our Lady of Loreto. Whereas the Madonna of Loreto is generally depicted in her Holy House, the birthplace of Jesus, enthroned and transported on the wings of angels, here she is depicted as a simple commoner in front of a doorway and holding the well lit Infant Jesus, who blesses pilgrims, common people kneeling down, wearing worn clothes and with dirty, bare feet. The idea of putting Madonna in direct contact with poor pilgrims was absolutely revolutionary and was much criticized.

Santa Maria della Pace the church groundwork on the site of the medieval chapel of Sant'Andrea de Acquaricariis. In the end of the 15th century. Pope Sisto IV commissioned its fabrication to Baccio Pontelli. The building while we know today is rebuilt by Pietro da Cortona, whose facade with a semicircular pronaos his architectural masterpiece and one of the greatest achievements of Roman Baroque architecture. After the discovery, the entire square became like a baroque theater, of which the church is an ideal stage. Inside the masterpieces of Raphael, Maderno and the Cloister of Bramante stand out.

The famous Contarelli Chapel, where you'll find Caravaggio's triptych composed of The Martyrdom of St. Matthew, The Vocation of St. Matthew and St. Matthew and the Angel, deserves a separate chapter. The chapel takes its name from Cardinal Mathieu Cointrel, later Italianized to Contarelli, who commissioned Michelangelo Merisi with the three altarpieces focused on the figure of San Matteo. The Martyrdom of San Matteo is the first canvas created by Caravaggio for the chapel. Compared to the others, the composition is overcrowded with a tangle of bodies that refers to Mannerism while the nudes are clear Michelangelesque elements.